docs: def size_on_disk(self):
          """
          :return: size of data and indices in bytes on the storage device
          """
          ret = self.connection.query(
              'SHOW TABLE STATUS FROM `{database}` WHERE NAME="{table}"'.format(
                  database=self.database, table=self.table_name), as_dict=True).fetchone()
          return ret['Data_length'] + ret['Index_length']